A current sensor channel may comprise a trans-impedance amplifier (TIA), a gain amplifier (GA) and a sample and hold (SH) circuit coupled in series to transform an input current into a voltage signal. The voltage signal is then converted to digital data by an analog-to-digital converter (ADC) for subsequent processing. While processing the data, the current sensor channel, due to its analog nature, may experience an offset associated with its individual component. For example, there may be an offset associated with the TIA and an offset associated with the GA. Furthermore, there may be an offset component caused by an environmental and/or process related factor associated with the current sensor channel. These offset components may vary between the channels and may vary over time.
A number of techniques for correcting the channel offset with the individual components, such as the TIA and GA, have been used. For example, an additional SH circuit may be added to the GA to sample and remove an offset associated with the TIA. In addition, a trimming circuit may also be added to trim the offset associated with the current sensor channel. However, analog offset correction using available tools may not be able to satisfactorily correct the channel offset. Moreover, some corrective measures often take significant chip resources in the design. For example, implementing a trimming circuit in the chip often takes up a sizable real estate in the chip, and it takes time to calibrate the trimming circuit in the factory. Additionally, the results obtained from the available tools may not be satisfactory as the channel offset may change with a parameter change in the channel as well as other environment related factors (e.g., temperature, humidity, etc.) and/or process related factors.